
(FPCore (x y) :precision binary64 (+ x (/ (- x y) 2.0)))
double code(double x, double y) {
return x + ((x - y) / 2.0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x + ((x - y) / 2.0d0)
end function
public static double code(double x, double y) {
return x + ((x - y) / 2.0);
}
def code(x, y): return x + ((x - y) / 2.0)
function code(x, y) return Float64(x + Float64(Float64(x - y) / 2.0)) end
function tmp = code(x, y) tmp = x + ((x - y) / 2.0); end
code[x_, y_] := N[(x + N[(N[(x - y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{x - y}{2}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (+ x (/ (- x y) 2.0)))
double code(double x, double y) {
return x + ((x - y) / 2.0);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x + ((x - y) / 2.0d0)
end function
public static double code(double x, double y) {
return x + ((x - y) / 2.0);
}
def code(x, y): return x + ((x - y) / 2.0)
function code(x, y) return Float64(x + Float64(Float64(x - y) / 2.0)) end
function tmp = code(x, y) tmp = x + ((x - y) / 2.0); end
code[x_, y_] := N[(x + N[(N[(x - y), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{x - y}{2}
\end{array}
(FPCore (x y) :precision binary64 (fma 1.5 x (* -0.5 y)))
double code(double x, double y) {
return fma(1.5, x, (-0.5 * y));
}
function code(x, y) return fma(1.5, x, Float64(-0.5 * y)) end
code[x_, y_] := N[(1.5 * x + N[(-0.5 * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(1.5, x, -0.5 \cdot y\right)
\end{array}
Initial program 99.9%
Taylor expanded in x around 0
+-commutativeN/A
lower-fma.f64N/A
lower-*.f64100.0
Applied rewrites100.0%
(FPCore (x y) :precision binary64 (if (or (<= x -2.1e+91) (not (<= x 1.05e-39))) (* 1.5 x) (* -0.5 y)))
double code(double x, double y) {
double tmp;
if ((x <= -2.1e+91) || !(x <= 1.05e-39)) {
tmp = 1.5 * x;
} else {
tmp = -0.5 * y;
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if ((x <= (-2.1d+91)) .or. (.not. (x <= 1.05d-39))) then
tmp = 1.5d0 * x
else
tmp = (-0.5d0) * y
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if ((x <= -2.1e+91) || !(x <= 1.05e-39)) {
tmp = 1.5 * x;
} else {
tmp = -0.5 * y;
}
return tmp;
}
def code(x, y): tmp = 0 if (x <= -2.1e+91) or not (x <= 1.05e-39): tmp = 1.5 * x else: tmp = -0.5 * y return tmp
function code(x, y) tmp = 0.0 if ((x <= -2.1e+91) || !(x <= 1.05e-39)) tmp = Float64(1.5 * x); else tmp = Float64(-0.5 * y); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if ((x <= -2.1e+91) || ~((x <= 1.05e-39))) tmp = 1.5 * x; else tmp = -0.5 * y; end tmp_2 = tmp; end
code[x_, y_] := If[Or[LessEqual[x, -2.1e+91], N[Not[LessEqual[x, 1.05e-39]], $MachinePrecision]], N[(1.5 * x), $MachinePrecision], N[(-0.5 * y), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.1 \cdot 10^{+91} \lor \neg \left(x \leq 1.05 \cdot 10^{-39}\right):\\
\;\;\;\;1.5 \cdot x\\
\mathbf{else}:\\
\;\;\;\;-0.5 \cdot y\\
\end{array}
\end{array}
if x < -2.10000000000000008e91 or 1.04999999999999997e-39 < x Initial program 99.8%
Taylor expanded in x around inf
lower-*.f6481.9
Applied rewrites81.9%
if -2.10000000000000008e91 < x < 1.04999999999999997e-39Initial program 100.0%
Taylor expanded in x around 0
lower-*.f6478.0
Applied rewrites78.0%
Final simplification79.5%
(FPCore (x y) :precision binary64 (* -0.5 y))
double code(double x, double y) {
return -0.5 * y;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (-0.5d0) * y
end function
public static double code(double x, double y) {
return -0.5 * y;
}
def code(x, y): return -0.5 * y
function code(x, y) return Float64(-0.5 * y) end
function tmp = code(x, y) tmp = -0.5 * y; end
code[x_, y_] := N[(-0.5 * y), $MachinePrecision]
\begin{array}{l}
\\
-0.5 \cdot y
\end{array}
Initial program 99.9%
Taylor expanded in x around 0
lower-*.f6456.2
Applied rewrites56.2%
(FPCore (x y) :precision binary64 (- (* 1.5 x) (* 0.5 y)))
double code(double x, double y) {
return (1.5 * x) - (0.5 * y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = (1.5d0 * x) - (0.5d0 * y)
end function
public static double code(double x, double y) {
return (1.5 * x) - (0.5 * y);
}
def code(x, y): return (1.5 * x) - (0.5 * y)
function code(x, y) return Float64(Float64(1.5 * x) - Float64(0.5 * y)) end
function tmp = code(x, y) tmp = (1.5 * x) - (0.5 * y); end
code[x_, y_] := N[(N[(1.5 * x), $MachinePrecision] - N[(0.5 * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1.5 \cdot x - 0.5 \cdot y
\end{array}
herbie shell --seed 2024339
(FPCore (x y)
:name "Graphics.Rendering.Chart.Axis.Types:hBufferRect from Chart-1.5.3"
:precision binary64
:alt
(! :herbie-platform default (- (* 3/2 x) (* 1/2 y)))
(+ x (/ (- x y) 2.0)))